1. Field of the Invention
The invention is related to the field of emergency services, and in particular, to networks, methods, and systems using bi-directional messaging for an emergency services network. More particularly, a conforming emergency system, such as a Public Safety Answering Point (PSAP), and a resource of an emergency services network establish an emergency event session during which either device may initiate and transmit multiple messages.
2. Statement of the Problem
In the United States, basic 9-1-1 service is an emergency reporting service where a calling party can dial 9-1-1 in emergency situations. The call is answered at a Public Safety Answering Point (PSAP, also known as a “Public Safety Access Point”). An operator at the PSAP converses with the calling party to determine information on the emergency situation. For instance, the operator may ask the calling party for his/her name, the nature of the emergency, and the location of the emergency, etc. Based on the information gathered by the operator, the operator then contacts emergency personnel to respond to the emergency.
Enhanced 9-1-1 service (E9-1-1) has the added feature of automatically providing the operator with some information on the calling party. For instance, E9-1-1 service includes the added features of Automatic Number Identification (ANI) and Automatic Location Identification (ALI). With Automatic Number Identification (ANI), the operator is automatically provided with telephone number of the phone placing the call for emergency services (e.g., a 9-1-1 call). With Automatic Location Identification (ALI), the PSAP, or another device, queries an ALI database for information on the physical location of the calling party's phone. An ALI database stores records of telephone numbers. A record in the ALI database contains information (such as a street address) on a physical location that corresponds with a telephone number. Responsive to a query from the PSAP, the ALI database returns the location information for the calling party. With the telephone number and the location information, the operator can more effectively handle the emergency call. Other countries have emergency services similar to this.
Traditional communication networks have a rigid architecture when it comes to connecting to an emergency services network. In a traditional communication network, a PSAP connects to a pair of ALI databases in the emergency services network. A pair of ALI databases is used for redundancy and reliability. The PSAP connects to each ALI database over a dedicated point-to-point connection. The ALI databases are the only resources in the emergency services network that connect with the PSAP.
One problem with current emergency services networks is that the PSAP-ALI interface model is a request-response model. The PSAP forwards a request for information to the ALI database, and the ALI database provides a single response to the PSAP. Under the current model, the PSAP has to initiate communication with the ALI database using a request. The ALI database is not allowed or equipped to initiate a communication with the PSAP and deliver information to the PSAP unless the PSAP first submits a request. The ALI database is also not allowed to transmit multiple messages to a PSAP responsive to a request. The ALI database is only allowed to transmit a single response message responsive to a request. The current PSAP-ALI interface model limits the types of enhanced services provided by the emergency services network.
Another problem with current emergency services networks is the traditional PSAP-ALI interface uses a limited message set. Most conventional PSAPs fundamentally include the same design as when they were initially conceived in the 1970's. The conventional PSAPs are configured to receive a fixed-length, pre-defined text string. The fixed-length text string limits the number of fields and the size of the fields that can be included in the text string. The small size of the text string severely constrains the amount of information that the ALI database can provide to the PSAP, the context that can be created, and the data types that can be supported. Emergency services administrators have had to “overload” the text string, using the same fixed-length field for multiple purposes in different contexts, to provide the current services. New services or new capabilities are very difficult to add if the text string is overloaded by the current services. For instance, an ALI database would not be able to provide or would only be able to provide very limited individual medical information to the PSAP. Also, the technology does not lend itself to streaming video to the PSAP as the traditional message set does not have the capacity.